I believe the expression is "God forbid"...e.g. ""I will be walking to work tomorrow,if,God forbid,my car is not running." Heard Mr.Bush say something on the news- "If God forbids"(plural).Which is correct?Is it not "God forbid'? Isn't this a use of the vestigial English subjunctive? Now,I am not sure on that one...you grammatical mavens out there can help me on this one.Also,isn't it the subjunctive being used in phrases like"May Jim have all of the best luck!"

The subjunctive in English can be characterized as vestigial...not used that much...used much more commonly in languages like French,Spanish,and others.It is a modal,used to express uncertainty,doubt,among other things.

Another interesting note...the Spanish word"Ojala"(often followed by a verbal phrase..the verb always being in the subjunctive)."Ojala"'s etymology comes from "O.Allah"...and is a reflection of Spain's Moorish.Muslim past.

Dear bnix,
I believe it is an example of the subjunctive, with elilpsis. The " full expression ", as you noted, would be, " May God forbid ( that ). ".Another ellipisis we often use is the expression " God willing " ( the Arabic " inshallah " ), which, of course, is the shortened form of " If God is willing ".
Yet another, also involving the Supreme Being, is, " Thank God ", with the subject being dropped. That's why many students here will say/write, " Thanks God ", instead. And, finally, still another, also having to do with the Creator, ( strange how so many of these are God-related ) is the famliar, " Bless you ", when someone sneezes, with the " May God " being dropped.
Regards,
John

You are correct.There is also ellipsis...the full expression being something like"May God forbid that would happen"...a little unwieldy,and very dated.So,we truncate it (elide?Is there a verb form of ellipsis?Got me on that one!) it to "God forbid".The subjunctive is used in phrases like this and similar ones,such as curses and imprecations,e.g."May God curse the ground you walk on...".etc. In Spanish it would be "Ojala que...(May Allah)....then a verb phrase containing the subjunctive form of the verb.

It is also interesting to note,that in former times,due to stricutures discouraging the use of the name of God in vain(i.e. using His name in curses,imprecations,etc),many forms were shortened or otherwise changed to circumvent those strictures.So,we have(or had...some are no longer in use,being archaic) expressions like Egad! and "Od's Bodkins(I believe a "bodkin" was a type of dagger or stiletto).And more current expressions like"Gosh"may have the same roots.

Listening to this Ivy League educated president speak off the cuff does makes you do a double-take every month or so. recently, what really got me was the way these 2 & 3 star types from Texas talk. Stuff like "it was shown pretty clear (sic) that... These fellahs all have done post graduate (mil or civilian schools) work, so i wonder if it's all calculated show, habit or what?
One funny phrase I heard is one I always home in on, as even my best
Japanese students would say, "Today is a historical day". I know that "historical society" is correct, but day and society have bit different meanings/usages.
The "cal" got on my nerves especially when J-landers said a "classical Corvette" ... but I imagine some USians make such errors now, too.

The "longer version is better" type mistakes are ridiculously pretentious sometimes .... i also want to ask if in the UK they have any slogans equal to " I support the troops" (whatever that could mean!) ...or the recent
"blue on blue" casualties.

Obviously a person who is well-versed in linguistic basics AND linguistic arcana.Encouraging and heartening to know there are a few people(at least ) in this field who actually know what they are doing.

Listening to this Ivy League educated president speak off the cuff does makes you do a double-take every month or so. recently, what really got me was the way these 2 & 3 star types from Texas talk. Stuff like "it was shown pretty clear (sic) that... These fellahs all have done post graduate (mil or civilian schools) work, so i wonder if it's all calculated show, habit or what?

For a lot of them it's a pretense IMO. For Bush, however, I think it's simply habit and the fact that he clearly has clinical problems in the speech department - he clearly isn't the brightest spark in the engine of state, which can't help either.